Hybrid vehicles using a combination of an internal combustion engine (ICE), an auxiliary drive source, and an energy storage unit are becoming more and more popular, due to their more efficient use of energy. In particular, the ICE can be operated intermittently and/or in a favorable operating regime, and braking energy can be recovered and stored for later use. The braking energy can be recovered and stored by an energy recovery device.
For efficient recovery of braking energy, it is desirable to transfer the braking energy substantially only to the energy recovery device and not to use braking energy for rotating the ICE. On the other hand, at least for hybrid vehicles of the parallel hybrid type, the ICE needs to be able to drive the driving wheels through the transmission.
Furthermore, it would be desirable to maintain flexibility in the vehicle design, for example in respect of type of transmission, ICE and energy recovery device, etc., while still fulfilling the often very severe space constraints of a modern car.
There is thus a need for hybrid vehicle with a very compact solution for allowing controllable torque transmission between the ICE and the transmission in such a way that the transmission can drive the energy recovery device during deceleration, and the ICE as well as the energy recovery device can drive the transmission during acceleration.